Police in Uganda say they suspect that fraud may have been the motive behind the killing of hundreds of followers of a Christian doomsday sect.

Officials told the BBC that they did not see the point of the recent mass killings, unless the intention of the sect leaders was to take money from their followers.

Members of the Movement for the Restoration of the Ten Commandments of God had been instructed to sell all their belongings in the days before their deaths, and had paid off all their debts.

Police are now trying to establish what happened to the money raised by the cult.

Third mass grave

Meanwhile, the discovery of a third mass grave has sparked fears that more victims of the cult violence may be found.

Police say 66 people were found in the grave at the home of one of the cult leaders, Dominic Kataribabo. The dead included 26 children and a pregnant woman.

It brings to over 700 the number of followers who have died or been murdered by the group.

There are a number of other properties that the poorly-resourced police have yet to examine, and the BBC correspondent in Uganda says there are now fears that many more bodies will be discovered.

A medical officer at the scene in the village of Rugazi in south-western Uganda said many of the victims had been tied up and there were signs of stabbing and strangulation.

Some bodies were buried three metres deep

Meanwhile, further disturbing details of the group are beginning to emerge.

Ever since up to 500 followers were incinerated in the cult's main church nearly two weeks ago, revelations have drawn a picture of a secretive, brutalising cult in which the leadership extorted money and demanded absolute obedience.

Police at first thought that members had participated in a mass suicide, but they changed their view after 150 bodies were found buried with machete wounds and other signs of violence under two rooms at a cult-owned property some 50 miles from the headquarters' site.

While it is thought that the former priest died in the church, one eyewitness said he saw the founder of the cult and a former prostitute-turned-mystic, leave before the fire.

Cult countdown

Jan-March: Killings begin, bodies buried in Buhunga

Early March: Members told to sell possessions

17 Mar: Church fire, Kanunga - mass suicide assumed

21 Mar: Six bodies exhumed from latrine

22 Mar: Police say bombs caused fire, murder suspected

24 Mar: 153 bodies found at sect compound, Buhunga

27 Mar: 70 bodies exhumed on leader's property

Investigators began digging on Mr Kataribabo's former property on Saturday, and discovered one body.

The exercise was suspended, but further digging on Monday revealed eight more bodies, some buried as deep as three metres (10 feet).

It is unusual for bodies to be buried together in mass graves without coffins in a part of Africa where it is considered very important to organise proper burials for the dead.